Calculator



Patented June 4, 1940 UNITED STATES PATENT OFFICE CALCULATOR Robert T.Frazier, Chattanooga, Tenn, assignor to Cavalier Corporation,Chattanooga, Tenn, a corporation of Tennessee Application November 6,1939, Serial No. 303,112

2 Claims. (Cl. 235-84) This invention is a novel improvement in calofthe e posed peripheral p n of disk culators, and the principal objectthereof is to Scale A denotes monetary values. provide a simplecalculator for determining the The upper or smallest disk B has acentral average cost at any given locality of operating field B whichmay be used for advertising pur- 5 ranges, refrigerators, water heaters,and the like, Doses, r or receiving printed s uct ons for byelectricity; also for determining the average using the Calculator, forOther imp d cost of operating such appliances by gas, whether adjacent ep p y of disk 3 is displayed the natural gas, manufactured or b ttl dgas; word Electricity. In the peripheral portion of also for comparingthe cost of electric and gas sk B is an index mark 32 for the P p eroperation of such a liances irrespective of f er de d, said p r ph l p nals 19 whether manufactured, natural, or bottled gas bearing an arrow B3m r ed R n e, an arrow is used at u h locality, Bt'marked Water heater,and an arrow B5 It frequently happens that salesmen for' gas markedRefrigerator, the arrows B3, B5 and and/or electric ranges,refrigerators, water heat- B5 pointing to t scale A On the intermediateers, and other appliances, are asked whether gas sk The Spacing 0n theinner d sk B, of or electric operation of such appliances is cheaper e rws B5 s ed on e a e a e in a given locality. If the salesman is handlingp wer n p n n ki w t hours of each of both types of apparatus he wouldnaturally be e ee app iances listeddesirous of installing the moreeconomic type of To determine t e e 00st o p on of 0 apparatus, but veryfew 521185111911 k h t such electric appliances, it is merely necessarymake the necessary cost calculations for comto re a e t e smaller orinner disk B on the parative purposes and th h do k h intermediate ormoney disk A to such position find that such calculations are difficultand timeha h ndex l ne B i s pp i the r e p r consuming. Use of my novelcalculator however, kilowatt hour on scale A for electricity at the whenproperly set according to the actual gas particular locality inquestion, and the average 25 and electric rates at such locality, willshow at t of Operation of an electric range, electric a glance threlative costs based upon th water heater, or electric refrigerator,based on tional averages of electric current and gas conthe nat av age0f Current Consumed, y sumed for such ranges, refrigerators, waterheaten be read d y on scale pp the 33 tars, or th appliances, arrows B3,B5 and B5, respectively.

I will explain the invention with reference to On e peripheral p n 0 t edisk C is the accompanying drawing which illustrates one n index ine C 3oopera t the legepractical embodiment thereof to enable others torithmie Scale A on the intermediate disk A. The adopt and use the same;and will summarize in periphery of the lower or large t disk C is p 35the claims, the novel features of construction, erably divided intothree seg e t e s n 35 and novel combinations of parts, for which proe ge notation Natural another tection is desired. segment C2 bearing thenotation Manufactured In said drawing: gasf; and a third segment C3bearing the nota- Fig. 1 is a top plan view of the calculator. tionBottled gas. In the segment C are ar- 40 Fig. 2 is a transverse sectiontherethrough on rows C4, C5 and C6, respectively marked Range, 40

the line 2-2, Fig. 1. Refrigerator, and Water heater, each ar- As shownin the drawing, my novel calculator row pointing towards the scale A onthe interpreferably comprises three superimposed disks mediate or moneydisk A. Similarly, in the e A, B, C, preferably of Celluloid or othersuitable ment C2 are three arrows C1, C8 and C9, respec- 43 relativelystiff material, the intermediate disk beively m rk Ran e, Refri 0r," ndW r 45 ing of larger diameter than the upper disk, and ter heater, eacharrow pointing to the scale A the lower disk being of larger diameterthan the on the intermediate disk A; and similarly in the intermediatedisk. The three disks are mounted segment C3 are three arrows Ciil, Cil, and CIZ, for relative rotation by means of an axially disrespectivelymarked Range, Refrigerator, and

1) posed pivot pin, rivet, or other means P, trans- Water heater, eacharrow also pointing to fixing the said disks. the scale A.

The exposed portion of the intermediate disk A The spacings of thearrows C4 to C12, respecbears a logarithmic scale A, includingconventively, on the gas disk C are based upon the ient subdivisionssimilarly to the ordinary slideaverage monthly consumption in hundredsof rule, said scale preferably extending the full width cubic feet ofmanufactured and natural gas.

For bottle gas, either propane or butane, sold at rates in cents perpound or per one-hundred pounds, the spacing is based on average fuelconsumption in pounds per month of each of the Manu- We ani asis g t. u.propane many Cu. fl. Cu. It. Liquid lbs. K WH Ban 9 1500 690 36.5 125Reir gerator 2000 920 4B. 7 Water heater 2500 1160 60. 8 250 Todetermine the average cost of operation of a gas range in a city wherenatural gas is used, the intermediate disk A is rotated on the disk Cuntil the rate per thousand cubic feet for natural gas, which applies tothat particular 10- cality, coincides with the index line CI3, and theaverage cost of operation of a range is read directly beneath the arrow04 marked Range in the natural gas segment C. If the average cost ofoperating a gas refrigerator is desired, the average cost maysimultaneously be read directly opposite the arrow C5 markedRefrigerator in the natural gas segment C. The average cost of operationof the water heater using natural gas may also be read directly oppositethe arrow C6 marked Water heater. Similarly, the average costs ofoperating on manufactured and bottle gas may be readily ascertained,using the related arrows in the segments C2 and C3 as the case may be,after setting the index line C|3 with respect to scale A in accordancewith the rates is then rotated upon disk A until the index line Wthereon points to the rate per kilowatt hour for electricity at thatsame locality. The cost of electrical operation 01 the range, therefrigerator, and the water heater may be read directly oppositethearrows B3, B4 and BI marked Range/P Refrigerator, or "Water heater."

I do not limit my invention to the exact form shown in the drawing forobviously changes may be made therein within the scope of the claims.

I claim:

l. A calculator for determining and comparing average costs of operationor electric and gas appliances, comprising three relatively rotatablecoaxial members; the intermediate member carrying at its periphery acircular logarithmic scale extending entirely across the exposedperipheral portion thereof; one end member having an index line and atleast one marking on its periphery cooperating with said scale, saidmarking being disposed with respect to the index line to accord with thenational average consumption of electric current for a given period foran electric appliance; and the other end member having an index line andat least one marking on its periphery cooperating with said scale, saidmarking being disposed with respect to the index line 01' the lastmentioned member to accord with the national average gas consumption fora like period for a gas appliance used for the same purpose as theelectric appliance.

2. A calculator for determining and comparing average costs of operationoi! electric and gas appliances, comprising three superimposedrelatively rotatable coaxial disks of progressively increasingdiameters; the intermediate disk carrying a circular logarithmic scaleextending entirely across its exposed peripheral portion; one end diskhaving an index line and at least one marking adjacent its peripherycooperating with said scale, said marking being disposed with respect tothe index line to accord with the national average consumption ofelectric current for a given period for an electric appliance; and theother end disk having an index line and at least one marking adjacentits periphery co0pcrating with said scale, said marking being disposedwith respect to the index line of the last mentioned disk to accord withthe national average gas consumption for a like period for a. gasappliance used for the same purpose as the electric appliance.

ROBERT T. FRAZIER.

